Russian columns are crossing into Ukraine: Nato commander

Nato’s top military commander has said that Russian tanks, troops, and artillery have been seen moving across the Ukraine border in the last few days, as fears grow of an intensified conflict in the area, media reports say.

Russia denies claims that its army has crossed into Ukraine.

US general Philip Breedlove, the overall head of allied forces in Europe, said the border had become "completely porous.” He said arms, men, and material were freely “flowing back and forth.”